Name Period Part I: INVESTIGATING OCEAN CURRENTS: PLOTTING BUOY DATA

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1 Name Period Part I: INVESTIGATING OCEAN CURRENTS: PLOTTING BUOY DATA INTRODUCTION: Ocean currents are like huge rivers in the sea. They carry drifting organisms, vital dissolved chemical nutrients and pollutants with them as they flow. Surface currents effect the biological productivity of the ocean and also help determine our climate by moving hot and cold water masses around. Currents are also important for ships traveling at sea that can move with or against the flow. In this investigation we will consider one important way that scientists gather information about the location and strength of ocean currents. The data below are from drifter buoys in the North Pacific Ocean. Released into the ocean, the buoys float with the currents and take measurements of the water with built-in instruments. They are tracked by satellites in orbits far above Earth and transmit data several times a day. The floater at the top of the buoy sits at the surface of the water and holds an antenna for sending data to a satellite above. Drogues well below the surface cause the ocean currents to take the buoy along instead of the surface wind The buoy also holds electronic instruments for measuring sea surface temperatures (SST), submergence, irradiance (for sunlight) and barometric pressure. At the top is another device for measuring temperature and conductivity (used to calculate salinity). PROCEDURES: Longitudes degrees on the left (west) side of the diagram are East Longitudes (positive numbers); longitudes 180 to 80 on the right (east) side of the diagram are West Longitudes (negative numbers). North Latitudes are in the upper half of the map and South Latitudes are in the lower half of the map. Label the numbers on the map as N and S latitudes and E and W longitudes. Use the longitude and latitude data below to plot the position of each buoy location during the year. Next, connect the locations with different color lines for each buoy and draw an arrow to show the direction of motion. ANALYSIS OF DATA: 1- Refer to a map of surface currents. What are the names of the surface currents that moved the buoys whose courses you plotted? (a) Buoy (b) Buoy (c) Buoy The currents plotted are all part of the North Pacific gyre, a clockwise-moving current that redistributes heat in the North Pacific. (a) What is the name of the current that moves water past the coast of California? (b) Do you think it carries warm or cold water past the coast of California? 3- Sometimes drifting buoys stop transmitting their data to orbiting satellites. (a) List several possibilities as to what might happen to a buoy drifting in the Pacific Ocean to interrupt its data stream. (b) How might these things be avoided? ACADEMIC CHALLENGE-- GEOGRAPHIC AND MATH EXTENSIONS: 4- Using a more detailed map or an atlas showing the Pacific Ocean with a distance scale, calculate approximately how far each buoy travelled overall during the months studied. 5- (a) How far did each buoy drift between February and March? (b) What was the speed of the current moving each buoy in kilometers per day? (c) miles per day? (d) kilometers per hour? (e) miles per hour? 6- Based on your calculations, rank the three surface currents according to their speed. 7- Based on your calculation for the California Current, how long would it take for plankton drifting off the coast of San Francisco to reach Santa Monica Bay? Part II-INVESTIGATING OCEAN CURRENTS AND CLIMATE Climate can be defined as the long term behavior of weather over time, including the average and extreme conditions for a region. Surface currents affect climate by moving cold and warm water around the globe. In general, currents carry warm water from the tropics toward the poles and bring cold water back toward the equator. A surface current warms or cools the air above it, influencing the climate of the land near the coast. Winds pick up moisture as they blow across warm water currents. This often brings mild rainy weather to the coastal regions. In contrast, cold water currents cool the air above them and since cold air has less of an ability to hold moisture than warm air, these currents tend to bring cool, dry weather to adjacent land areas. Fog is often found along the land sea borders where cold ocean currents exist. An example is the west coast of South America where fog is found off the coast and the driest desert in the world, the Atacama, exists!

2 A climograph is a special type of graph that displays the monthly average precipitation and temperature for an area over the course of a year. By studying climographs, you can see how precipitation and temperature differ from one community to another. Procedure: 1.) Look at the map of major ocean currents and write a prediction describing the climate you would expect of each place listed below. (The symbols are to help locate the cities on the world map.) a.) Arica, Chile (along the Peru Current) b.) Trondhiem, Norway (along the Norwegian Current) c.) Tokyo, Japan along the (Kuroshio Current) 2.) Using the climate data from Fact Sheet A, create a climograph for each city listed. Use a line graph for temperature and a bar graph for precipitation on the same graph. 3.) Answer the analysis questions below a.) Examine your climographs. What is the difference between the highest and lowest temperatures in the climograph for each city? b.) Which city is in a desert? How can you tell? c.) d.) Take a closer look at the Arica, Chile climograph. What can you tell about the seasons and the months? How is this related to the hemisphere where Arica is located? Is there a relationship between the temperature of the ocean current and the coastal climate? e.) f.) Is there a relationship between the direction of the ocean current and the coastal climate? In general, on which side of the ocean basins are the cold currents? Warm currents? g.) What can you infer about the climate of each region by reviewing these climographs?

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5 Part I- BUOY DATA Buoy no Position day Latitude Longitude Feb Mar Apr May June July Aug Sept Nov Dec Feb Mar Apr May June July Aug Sept Oct Nov Dec Feb Mar Apr May June July Aug Sept Oct Nov Dec